How to get list of projects in current Visual studio solution?

Question

When we open Package Manager Console in any open solution, it shows all the projects of that solution. How it is loading all the projects of the same solution. When I tried

Answer 1

There may be a nicer way but I had a quick go at this and found this to work (it assumes you have a way of knowing the solution name). According to this post, GetActiveObject does not guarantee the current instance of VS which is why you're getting results from another instance. Instead, you can use the GetDTE method shown there:

[DllImport("ole32.dll")]
private static extern int CreateBindCtx(uint reserved, out IBindCtx ppbc);

public static DTE GetDTE(int processId)
{
    string progId = "!VisualStudio.DTE.10.0:" + processId.ToString();
    object runningObject = null;

    IBindCtx bindCtx = null;
    IRunningObjectTable rot = null;
    IEnumMoniker enumMonikers = null;

    try
    {
        Marshal.ThrowExceptionForHR(CreateBindCtx(reserved: 0, ppbc: out bindCtx));
        bindCtx.GetRunningObjectTable(out rot);
        rot.EnumRunning(out enumMonikers);

        IMoniker[] moniker = new IMoniker[1];
        IntPtr numberFetched = IntPtr.Zero;
        while (enumMonikers.Next(1, moniker, numberFetched) == 0)
        {
            IMoniker runningObjectMoniker = moniker[0];

            string name = null;

            try
            {
                if (runningObjectMoniker != null)
                {
                    runningObjectMoniker.GetDisplayName(bindCtx, null, out name);
                }
            }
            catch (UnauthorizedAccessException)
            {
                // Do nothing, there is something in the ROT that we do not have access to.
            }

            if (!string.IsNullOrEmpty(name) && string.Equals(name, progId, StringComparison.Ordinal))
            {
                Marshal.ThrowExceptionForHR(rot.GetObject(runningObjectMoniker, out runningObject));
                break;
            }
        }
    }
    finally
    {
        if (enumMonikers != null)
        {
            Marshal.ReleaseComObject(enumMonikers);
        }

        if (rot != null)
        {
            Marshal.ReleaseComObject(rot);
        }

        if (bindCtx != null)
        {
            Marshal.ReleaseComObject(bindCtx);
        }
    }

    return (DTE)runningObject;
} 

If you know the solution name in advance, you can find it in the MainWindowTitle property of Process and pass the ProcessID to the method above.

var dte = GetDTE(System.Diagnostics.Process.GetProcesses().Where(x => x.MainWindowTitle.StartsWith("SolutionName") && x.ProcessName.Contains("devenv")).FirstOrDefault().Id);

Whilst the above code worked, I encountered a COM error which I fixed by using the MessageFilter class shown here.

From that post, this is what the MessageFilter class looks like

public class MessageFilter : IOleMessageFilter
{            
    // Class containing the IOleMessageFilter
    // thread error-handling functions.

    // Start the filter.
    public static void Register()
    {
        IOleMessageFilter newFilter = new MessageFilter();
        IOleMessageFilter oldFilter = null;
        CoRegisterMessageFilter(newFilter, out oldFilter);
    }


    // Done with the filter, close it.
    public static void Revoke()
    {
        IOleMessageFilter oldFilter = null;
        CoRegisterMessageFilter(null, out oldFilter);
    }


    //
    // IOleMessageFilter functions.
    // Handle incoming thread requests.
    int IOleMessageFilter.HandleInComingCall(int dwCallType,
    System.IntPtr hTaskCaller, int dwTickCount, System.IntPtr lpInterfaceInfo)
    {

        //Return the flag SERVERCALL_ISHANDLED.
        return 0;
    }


    // Thread call was rejected, so try again.
    int IOleMessageFilter.RetryRejectedCall(System.IntPtr
    hTaskCallee, int dwTickCount, int dwRejectType)
    {

        if (dwRejectType == 2)
        // flag = SERVERCALL_RETRYLATER.
        {
            // Retry the thread call immediately if return >=0 &
            // <100.
            return 99;
        }
        // Too busy; cancel call.
        return -1;
    }


    int IOleMessageFilter.MessagePending(System.IntPtr hTaskCallee,
    int dwTickCount, int dwPendingType)
    {
        //Return the flag PENDINGMSG_WAITDEFPROCESS.
        return 2;
    }


    // Implement the IOleMessageFilter interface.
    [DllImport("Ole32.dll")]
    private static extern int
      CoRegisterMessageFilter(IOleMessageFilter newFilter, out
      IOleMessageFilter oldFilter);
}



[ComImport(), Guid("00000016-0000-0000-C000-000000000046"),
InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)]
interface IOleMessageFilter
{
    [PreserveSig]
    int HandleInComingCall(
    int dwCallType,
    IntPtr hTaskCaller,
    int dwTickCount,
    IntPtr lpInterfaceInfo);

    [PreserveSig]
    int RetryRejectedCall(
    IntPtr hTaskCallee,
    int dwTickCount,
    int dwRejectType);


    [PreserveSig]
    int MessagePending(
        IntPtr hTaskCallee,
        int dwTickCount,
        int dwPendingType);
}

Then you can access the project names like this

var dte = GetDTE(System.Diagnostics.Process.GetProcesses().Where(x => x.MainWindowTitle.StartsWith("SolutionName") && x.ProcessName.Contains("devenv")).FirstOrDefault().Id);
MessageFilter.Register();
var projects = dte.Solution.OfType().ToList();
MessageFilter.Revoke();

foreach (var proj in projects)
{
   Debug.WriteLine(proj.Name);
}

Marshal.ReleaseComObject(dte);